whittemore



I Aug. 28, 1923. 1,466.460

J. WHITTEMORE METHOD AND APPARATUS FOR DRAWING AND FLATTENING SHEET GLASS Filed Nov. 26, 1920 s Sheet s-Sheet 1 INVENTQR o 26 BY ATTVOR EY Aug. 28, 1923.

-J. WHITTEMORE METHOD AND APPARATUS FOR DRAWING AND FLATTENING SHEET GLASS Filed Nov. 26 1920 3 Sheets-Sheet 2 I. R m W E v n M 5 w BY p ATTORNEY Aug. 28, 1923. 1,466.460

J. WHITTEMORE METHOD AND APPARATUS FOR DRAWING AND FLATTENING SHEET GLASS Filed Nov. 26, 1920 S Sheets-Sheet 3 INVENTOR ATTORNEY Patented Aug. 28, 1923.

UNITED STATES PATENT OFFICE.

JAMES WHITTEMORE, OF DETROIT, hIICI-IIGAN, ASSIGNOR TO THE LIBBEY-OXVENS SHEET GLASS COMPANY, OF TOLEDO, OHIO, A CORPORATION OF OHIO.

METHOD AND APPARATUS FOR DRA'WING AND FLATTENING SHEET GLASS.

Application filed November 26, 1920. Serial No. 428,377.

1 '0 all whom it may canoe 1m,

Be it known that 1, JAMES ivnrrrmroim, a citizen of the United States, residing at Detroit, in the county of Wayne and fitate of Michigan, have invented new and useful Improvements in Methods and Apparatus for Drawing and l lattening Sheet Glass, of which the following is a specification.

This invention relates to the art of drawing glass in sheet form from a mass of molten glass, and is concerned more particularly with a process and apparatus tor stretching the drawn sheet laterally to flat ten the same and improve the quality.

Although this invention could be used in connection with any form of sheet drawing process, it is here shown as adapted for use with the term of apparatus disclosed in the patent to 1. WV. Golburn, 1,248,809, granted Dec. 1, 1917. In this patented apparatus, a sheet of glass is drawn upwardly from a bath or molten glass, bent into a horizontal plane, reheated, and then passed through a drawing mechanism which furnishes the required longitudinal pull to produce the continuous sheet of glass and at the same time flattens the reheated sheet into its final TOIHI. This present invention includes a mecha nism for intermittently grasping the opposite edges of the sheet and pulling the same forwardly and outwardly to impart a lateral tension and stretching action to the sheet. While the sheet might be so stretched at any point where it remains in a semi-plastic and workable condition, the stretchers are here applied to the reheated sheet after being bent into the horizontal plane, and before the sheet enters the drawing mechanism.

The peculiar nature and objects 01 the invention will become more apparent as the detailed description proceeds.

Referring to the accompanying drawmgs:

Fig. 1 is a partial horizontal section, substantially on the line 11 of Fig. 2, the stretching mechanism being shown in plan.

Fig. 2 is a side elevation, partly broken away, of a portion of the sheet drawing apparatus, the stretching mechanism belng 111- dicated in side elevation.

Fig. 3 is a front elevation of part of the stretching mechanism at one side of the sheet, the view being taken substantially on the line III-III of Fig. 1. This View is on an enlarged scale.

Fig. at is a similar View showing the grippers disengaged from the sheet while on their return stroke.

Fig. 5 is an enlarged plan view of that portion of the stretcher operating mechanism, located outside of the sheet drawing machine, the par s being in position to commence the working stroke.

Fig. (5 is a partial plan similar to Fig. 5, with the parts near the end of the working stroke.

Fig. 7 is an outer end elevation of the stretcher ope 'ating mechanism.

Fig. 8 is a detail elevation of the cam mechanism for clamping the grippers onto the glass sheet.

Fig. 9 is a plan detail of the main operating cam, and

Fig. 10 is an elevation of the sliding closure tor sealing the opening at the side of the sheet drawing machine.

Referring first to Figs. 1 and 2, it will be seen that the glass sheet 1 is drawn up from the mass of molten glass 2 in receptacle 3, between coolers 4; and edge-maintaining rollers 5, all as more clearly set forth in the Uolburn patent above noted. At 6 is an internally cooled roller over which the sheet is bent into a horizontal plane, and is then drawn otf laterally over suitable idler rollers 7, by the drawing mechanism 8. At 9 are located suitable burners or other heating devices to reheat and soften the sheet, so that it may be stretched out and flattened. It is the particular objectof the present invention, as here illustrated to grip the edges of this reheated sheet, at a point intermediate the bending roller and the drawing mechanism, and stretch the sheet laterally to flatten the same and help remove wrinkles and waves.

The two gripping and stretching mechanisms at the opposite sides of the sheet are substantial duplicates, except that the parts are rcve used so that they may operate from opposite sides, and only one of them need be described. A pair of gripping members 10, one above the sheet edge and the other below, are carried pivotally at 18 at the inner ends of a pair of levers 11, which are pivoted at their outer ends on a short horizontal trunnion 12, carried by a frame 13, vertically pivoted at 1 1 in a stationary supporting bracket 15. A pair of rods 16, of equal length with the levers 11, are pivoted li i) at their inner ends at 17 to the 'rippers l0, and the outer ends of rods '16, are horizontally pivoted in a stud 19, Vertically pivoted at 20 in an extension of bracket if). The distance 18..l7 is the same as distance l e-20, so that the grippers 10 when swung in an are about the pivot 14:, will he forced to maintain their longitudinal centerline parallel with the sheet edges. The grippers 10 are adapted to swing, while in engagement withv the sheet, from the lull-line posilllOllSllO V11 in l ig. 1 to the dotted-line position, then release the sheet and return to the initial position and repeat the operation. It will be seen from an inspection 01 Fig. 1 that at the start of the working stroke the levers 11 are 'ierpendicular to the edge of the sheet, and that as the grippers swing forwardly with the sheet they also swing outwardly about the center i l, thus stretching the sheet laterally. The grippers 10 are of such a length with respect to the length of the working stroke, that the portions of the sheet edge gripped in succeeding strokes overlap as to stretch all parts or the sheet to a substantially equal degree.

The remainder of the mechanism, now to be described, is designed to automatically and continuously more the grippers into ongagement with the sheet edge, then carry them forward with the sheet at the same speed as the sheet, then release the sheet and return the rippers rapidly to the first poto sition. 'llhe mechanism shown is merely one form adapted to carry out these functions and could obviously be changed in many particulars without departii'ig from the tun dainental principles of this invention.

A lever extension-21, of frame 13, carries a roller engz ring coutinuoi'lsly in the cam-slot 23, ot' horizontal cam 24. The cam 24; is carried at the upper end. of a Vertical shaft 25, journaled in bracket 15 and driven continuously and at a constant speed through bevel. gearing 26, tirointhe drive shaft 27. The canislot 23, as shown more clearly in Fig. 9 has a continuously rising portion u-ocd throughout about threequarters of its length, and then a quickly de eending portion (IL-u through the remaining quarter. 'l. he ram being rotate il continuously in the direction of the arrow in Fig. 5, will swing the grippers slowly and evenly forward at the speed of the sheet while the roller 22 is in the portion (i-Z)-0(Z ot the cam, and will then return the grippers quickly to the starting. position while roller 22 is in the portion (E e.

At an intermediate point in the length of lovers 11. are secured a pair 01 "nits 2S, pivoted at their inner ends to slide-block 29. which is slid-ably mounted on supportingrod 30. Rod 30 is joined at its outer end to frame 13, and at its inner end is mounted a egieo roller 31, traveling on fixed trackway 32. Secured at one end in slide-.bl0ck29 is a rod 32%, which is slida-bly mounted adjacent its other end through a boss 3st on frame 13. Mounted on 'rod between block and boss 34: is an expansion spring The normal tendency of spring 35 is to force block 29 inwardly, and, through the toggle formed by links 328, spread the levers ii, and thence force the grippers 10 away from the sheet 1. It bracket 36 projects out and up from sup porting bracket 15, and carries on its upper face a Vertical cain track iii", con'iprising a stationery part 38 and a pivoted section 39. Pivoted section 39 is normally held against abutment 42, in the position shown in 6 by spring ll), but may he swung aside against the action of the spring as hereiner specified. ()n the outer end of rod 33,, adjustably secured by set-screw s9, is an elbow ineinber carrying a roller il, designed to cooperate with the earn-track Si. in the position shown in igs. l,- 6 and 8, the roller s1 is out of engagement with'oain 8'7 and the grippers 1O have'been released from the secret 1, through the action of spring and cooperating parts, as already do. ribed. As the grippers are now swung quiclily back on the return stroke the roller will push. by the yielding section lf) ot the rain-track, which after the passage of the roller will be snapped back by spring a l) against the abutment '42. At the start of the working strolre,-the roller ll will be forced up on the cam-track 37, thus pulling the rod Failrrutwardl; and, through toggle clamping the grippers 10 onto the sheet, end or the working stroke, the roller ll runs oil the end of cam-track 37, and spring once more releases the ppers. The adjustment 419 is provided tor varying the ef fective lengthol rod and consequently the distance between grippers 1.0 when in operative position Adjusting nuts limit the inward movement of rod 33, and hence the spreading ot grippers 10, when roller 41:1, is out oi engagement with rain 37;

ln order to permit the operation oi the lovers l1 and rods 16, openings :3 must be provided in the sides oii-the enclosing casing for the machine. prevent in so tar as possible the escape oi? heat through these openings, sliding closures 44 are provided. one or these closures being more clearly illustrated in Fig. 10; The closure snugly against the outer side ot the casing, and is slidably mounted on rollers The levers 11 operate through suitable apertures 16 in the closure, and carry the closure back and forth with them, as they reciprocate. Rods 16 operate through similar passages LT.

filter the sheet drawing mechanism has been set in operation, and the sheet is passing continuously through the machine, the operation of the grippers 10 is started and fit the V continued as already described. These grippers function to flatten out and improve the quality 01'' the drawn sheet, without impeding the drawing operation as now performed. It obvious that with slight alterations in the design of the mechanism, the grippers could be applied at other points along either the vertical or horizontal run of the sheet. the only requisite being that the sheet be in a sufliciently plastic condition at that point to undergo the stretching operation.

Claims:

1. The method of drawing and flattening sheet glass, consisting in drawing a sheet of glass from a molten source, deflecting the sheet into another plane, reheating the sheet, and stretching the reheated sheet laterally, while the sheet is being continuously drawn longitudinally by an advanced section of the sheet.

2. The method of drawing and flattening sheet glass, consisting in drawing a sheet of glass from a mass of molten glass, bending the sheet into a horizontal plane, reheating and softening the sheet, gripping the edge portions of the reheated portion of the sheet and stretching the sheet laterally during its travel, and simultaneously, but on another portion of the sheet applying longitudinal draft to continue the drawing operation.

3. The method of drawing and flattening sheet glass, consisting in drawing a sheet of glass continuously from a molten source, and at a point intermediate the sheet source and the drawing means intermittently and successively grasping substantial longitudinal sections of the opposite edge portions of the sheet and stretching the sheet laterally, the sheet being grasped at such frequent intervals that the sections successively grasped overlap one another.

l. The method of stretching and flattening sheet glass, consisting in continuously drawing the sheet from a molten source, reheating and softening the sheet, and then at a point intermediate the reheating means and the drawing means intermittently grasping opposite sections of the edge portions of the reheated sheet and drawing same longitudinally and laterally, so as to stretch the sheet without interrupting .its continuous produc tion.

5. In an apparatus for drawing sheet glass, wherein the sheet is drawn upwardly from a mass of molten glass, bent into a horizontal plane, reheated and longitudinal draft applied thereto, stretching devices comprising grippers for graspingthe edge portions of the reheated sheet before it reaches the drawing mechanism, and pulling the edges outwardly to flatten the sheet.

6. In an apparatus for drawing and flattening shee't glass, a receptacle containing a mass of molten glass from which the sheet is drawn upwardly, means for bending the drawn sheet into a horizontal plane, means for reheating and softening the sheet, means for applying the longitudinal draft to the sheeet, and means for grasping the edge portions of the softened sheet between the bend ing device and the drawing means, and stretching the sheet laterally to flatten the same and remove waves and wrinkles.

7. In an apparatus for drawing sheet glass, wherein the sheet is drawn upwardly from a mass of molten glass, bent into a horizontal plane, reheated and drawn oif horizontally, sheet-stretching and flattening mechanism comprising, a pairof grippers for simultaneously engaging substantial portions of the opposite edges of the reheated sheet, means for simultaneously moving the grippers forwardly and outwardly and for returning the grippers to initial position, and means to engage the grippers with the sheet at the beginning of the forward movement and disengage them before the return movemcut,the portions oi. the sheet edges grasped by successive operations of the grippers overlapping so that a practically uniform stretch is given to the sheet.

8. In any apparatus for stretching continuously drawn sheet glass, grippers for engaging opposite sections of the edge portions of the sheet, levers carrying the grippers and swinging them forwardly and outwardly in the plane or the sheet, cam means acting through the levers to move the grippers torwardly at the speed of the sheet and then quickly return the grippers to starting posi tion, and means for clamping the grippers to the sheet during the forward stroke and releasing them during the return stroke.

Signed at Toledo, in the county of Lucas and State of Ohio, this 23d day of Nov.,

JAMES WHITTEMORE. 

